Does anyone know if isolation valves on a multiple chiller plant are required by ASHRAE, or they simply best practice?
I have looked into this in ASHRAE documents, but have not found anything yet. I do know for a fact that a non-operating chiller will pass water without cooling it and eventually mix with the cooled water leaving the operating chiller producing a mixed chilled water temperature that will be higher than setpoint to the load (proportional to the flows of each chiller).
I obviously get resistance from the installing contractors due to monetary issues.